The Effect of Vaginal Progesterone in Reducing Preterm Birth in Women With an Increased Uterocervical Angle: A Randomized Controlled Trial Publisher



Borna S ; Eshraghi N ; Hantoushzadeh S ; Vahdani FG ; Panahi Z ; Jafarabady K ; Farshidfar B ; Saedi N
Source: Journal of Nursing and Midwifery Sciences Published:2025

Abstract

Background: Preterm birth (PTB) is a leading cause of perinatal mortality. Identifying women at high risk of PTB and implementing effective prevention strategies are essential for improving neonatal outcomes. Objectives: The present study aimed to evaluate the effectiveness of vaginal progesterone in reducing PTB among pregnant women with an increased uterocervical angle (UCA). Methods: In this randomized clinical trial conducted at Imam-Khomeini Hospital Complex, Tehran, Iran, from January to December 2024, fifty-two pregnant women between 18 and 20 weeks of gestation with cervical length (CL) ≥ 30 mm and a UCA > 105° were enrolled. Participants were randomly assigned to an intervention or control group using a simple randomization method. The intervention group received 400 mg of vaginal progesterone suppositories daily from 18-20 weeks until 36 weeks of gestation, while the control group received no progesterone. Statistical analyses included descriptive statistics, independent t-test, chi-square or Fisher’s exact test, and regression analysis. Results: The intervention group had a significantly higher mean gestational age at delivery (269.7 ± 8.6 days) compared to the control group (262.0 ± 15.4 days; P = 0.031). The incidence of PTB was significantly lower in the intervention group (7.7%) versus the control group (34.6%; P = 0.038). Regression analysis indicated that progesterone administration was associated with a significantly reduced risk of PTB (OR 0.14, 95% CI 0.02-0.79, P = 0.026). Conclusions: Vaginal progesterone may serve as an effective prophylactic intervention to reduce PTB in women with a normal CL but increased UCA. It is a safe, accessible, and affordable strategy for PTB prevention in this subgroup. © 2025 Elsevier B.V., All rights reserved.